Critics were less than impressed, and also frustrated by the lengths Google has gone to avoid the issue. Rather than deal with the well-documented problems of click farms and fraudulent publisher clicks, critics charge that Google chose the annual gathering of industry faithful to attack the messengers.

The objects of Google's ire are third-party click fraud auditing firms that, according to Google, "significantly overestimate" how much click fraud they detect.

The culprits, according to Google, are mysterious "fictitious clicks" that allegedly can inflate the amount of "click fraud" in the audits by as much as fivefold.

Apparently, when searchers click "back" while on a site accessed through a landing page, reload while on a landing page, or open a new window in Microsoft's Internet Explorer causing a landing page to reload, more clicks are reported than are actually recorded in Google's AdWords.

Advertisers are billed based on the AdWords accounting, not the artificially inflated figures reported by the third-party firms - no harm, no foul, says Google.

So if the third-party audit estimates are wrong, what are the right numbers? Several times in its report, Google brings us to the logical brink: "their numbers are wrong, the correct numbers are ..." But the second shoe never drops. If it did, some allege that Google would have to admit that a serious problem exists, and so far it's been in the company's interest to ignore it.

For example, in the paper Google assails a report on the "perception of click fraud done by Outsell." Google says, "Thus the report's (Outsell's) conclusions about the percentage of fraud and financial loss for the industry are essentially a poll of the perceptions of the problem ... rather than actual size of the problem."

So what is the actual size? Cynics in the search engine optimization industry say Google wants us to believe that the entire problem is "fictitious."

Search engine marketing firms such as ours regularly uncover cases of obvious click fraud, and Google credits our clients accordingly. These can't be explained away as "fictitious clicks." It requires constant vigilance and considerable time on behalf of clients. Many of us believe Google's time would be better spent solving the problem rather than trivializing it.

To the advertiser, the problem is relatively simple: Somebody is running up the meter. Because only three parties could profit from such fraud - publishers, competitors and the engines who sell the ads - an objective fourth party, like an independent auditor, still makes a lot of sense.